Intraocular Metastasis from an Anal Squamous Cell Carcinoma: A Case Report

Background: Anal cancer is a relatively less common gastrointestinal cancer, with common sites of metastasis being para-aortic nodes, liver, lungs, and skin. Intraocular metastasis from anal squamous cell carcinoma is an extremely rare occurrence with no reported cases so far. Case Description: We present a case of a 70-year-old male with a past medical history of metastatic anal squamous cell carcinoma who presented to the oncology clinic with complaints of sudden onset complete vision loss in his right eye. Patient was then referred to a retina specialist and was found to have a posterior choroidal tumor that raised concerns of a primary uveal melanoma vs metastatic spread from his known primary cancer. He underwent right eye enucleation and prosthesis placement with pathology confirming metastatic carcinoma consistent with anal carcinoma. Conclusion: This case presents the rare phenomenon of intraorbital metastasis from a primary anal squamous cell carcinoma. Per our literature review, this is the only reported case of such an occurrence, which adds to the clinical complexity of this case in terms of timely diagnosis, effective treatment modalities and prognosis.